Retarded latch trip circuit breaker



April 18, 1950 L. R. LUDWIG ETAT. 2,504,855

RETARDED LATCH TRIP CIRCUIT BREAKER Filed June 9, 1944 3 Sheets-Sheet 1WITNESSES: INVENTORS M e077 E. L z/dzaz'g, w27/iam Smal/@zzz f j andgag/776D. a/fzel.

April 18, 1950 1 R. LUDWIG ETAL 2,504,855

RETARDED LATCH TRIP CIRCUIT BREAKER Filed June 9, 1944. 3 Sheets-Sheet 2lNvENToRs 072 adm/y, Wifi/m72 H 57i/.allem and Jay/26j?. Gaz/zei.

5 Sheets-Sheet 5 L R LUDWIG ET AL RETARDED LATCH TRIP CIRCUIT BREAKERApril 18, 1950 Filed June 9, 1944 laf Z/zz/azzbrz WITNESSES:

Patented Apr. 18, 1950 UNITED' STATES PATENT OFFICE RETEBED LATCH TRIPCIR-CUIT REAKR of Pennsylvania ApplicationJule 9, 1944, Serial No.-539,450

(Cl. 200e-108') 9`r Claims, 1

'Ihisinvention relates to circuit breakersand, more particularly tocircuit breakers embodying electroniagneticv itri-gzapingV mea-ns forinstantaneously tripping the 'breaker in response to overload currentsabove ay predetermined value andrfafter atime-delayv in. response toeverloads ofgl'esser value@ Certain feat.ure s.disclesed but not claimedin this; applicatierinA are' tullydiscosed and claimed invcopendingdivisional application, Serial No. 42,314, filed Augn; 194g, by Leon R.Ludwig, Will-iam H. Stnelleinand GayneD. Gamel and assignedtoA theassignee of.A thel present invention.

Anobiectdiaf theinvention is to provide a circuit breaker having anelectromagnetic trip device with an ir`r1proved,a djustavble time-delaydevice Whichfis alsofeffectiveto prevent tripping ofthe breaker. as a:resultv Qisudden, shocks or jarring forces.

AnotherJ object; of ,thei invention. is to provide a circuitY breakernavi-ngen electromagnetic trip device Withy an improved mechanicallime-delay device Whichprevents trip-pingfcf the breaker in response toshocksorf jarring orcesbut which permits instantaneous tripping of thebreaker.-

Another object oftherinventionis to provide k.a circuit breaker havingan electromagnetic/trip devicez with a` timegdelay` device comprising amechanical-escapement-- mechanisln-` which prevents.` trippingv ofthe-breakerink response t0 shocks andk jarring forces-.bute whichpermitsw instantaneous and] time-delay tripping` of the brjeakerin;response to overload currents occurring duringthe existence of vshocksor jarring for-ces.

Another .obiectof the invention to provide a multi-pele circuitbreakerhaving l an electromagnetictrip deviceY associated with each of.ratleast tvvopoles ofthe breaker Withvra singletime-delay device disposedin a, manner topermit instantaneous and time-delay trippinjgfof; the`breaker but which prevent's-trippinggor` the breaker-inl response toshocks' or. j arriba-forces.

Another object" of 'the-:invention is to provide a multiepolecircuitbreaker having an electromagnetic trip device-.associatedwitheach of,V a least tv /opoles' of:y the breaker Witha.v singletime-delay device commento said trip devices for Ydelaying tripping Yof'the breaker by said;v trip devices, the time-delay device :preventingtripping of the breaker: in'responselto shocksl or jarring forces.,andan electromagnetic trip device: operable independentlyv of.'` saidtime-delay device to trip the breaker.

Anotherobject ot the-:invention is to provide 2 a circuit breakerhaving` a. plurality of electromagnetic. tripHdevices-with a latchmember` oper-l able in one direction by one of said trip devices totrip` the breaker and operable in another direction by another. ofl saidtrip devices to trip the breaker,-V said` one trip-device being providedwith. a time-delay device 'to delay tripping of the breaker by each ofsaid trip devices Whichtimedelay device also prevents tripping of thebreaker bysaid` trip devices in responseto shocks andjarforces, thecircuit breaker being` also provided with electromagnetic trip deviceoperable to. trip` the breaker independently of the tiniedelay deviceandmeans toprevent tripping operation of said independent trip device inresponse to shocks and jarringforces..

Another object of the invention is to provide a circuit breaker with anoveltrip mechanism wherein a latch member is rotated by anelectromagnetic trip device to trip the breaker, the latch member beingmoved axially by a second electro magnetj trip device to trip thebreaker. n

In accordance With/.the invention, there is provided a circuit breakerhavingV a main; latch that is movable rotatably by anyone of a pluralityof trip devices. A single time-delay device is provided to/delay therotary tripping movement of theiatch and to prevent rotary trippingmovement.y ci thev latchin response to shocks. There is furtherprovidedg a separate'trip device for moving the latch axiallyindependently oil` the time-delay device totrip the breaker, andV a,separate shock-prooi device for preventing axial movement othe latch inresponse to shocks.`

Thenovel ieaturesfthat are considered `characteristics of the inventionare set forth in particular in the appended claims.. The inventionitself, however, both as to structure and operation, together withadditional objects and advantages thereof, will be best understood lfromthe following detailed description of oneembcdiment thereciwhenreadinconjunctionwth the accompany ing drawings, in which:

Figure i, is a verticalsectional View through theV center poleroi athree-pole circuit breaker embodying the principles of the invention;

2 is anenlarged vertical sectional view of the tripmechanism;

Fig. 3 is a horizontal sectional View of thetrip mechanism taken on lineIII-.lil of Fig. 2, showing the time-delay device.

Fig. 4 isa sectional view taken on line IV--IV of Fig. 2.

Fig.- 5 is afragmentary view partly inY section online V-V of Fig.2showingthe latcbmechani'sm.

Fig. 6 is a sectional view taken on line VI-VI of Fig. 2 showing thecooperation of the latch member with the tripping toggle.

Fig. '1 is a sectional view taken on line VII--VII of Fig. 2.

Referring to Fig. l of the drawings, the circuit breaker is providedwith an operating mechanism common to all of the poles of the breaker.The operating mechanism is mounted in a U-shaped frame I1 having sideswhich are rigidly connected by a cross member I9. The frame I1 ismounted on the central portion of a-base II of insulating material andis secured thereto by means of bolts 2| and 23. The outer ends of theframe are rigidly connected by a cross-member 25.

A shaft 29 extending through. openings in the sides oi the frame I1pivotally supports a pair of A contact-arms 3| having `their free endsintegral with a contact-arm 30 for the center pole. The contact-arms(not shown) for the outer poles of the breaker are identical with thecontact arm 30 for the center pole, but are not provided with arms 3|.rIhe contact-arms for the outer poles are rigidly secured to a tie-bar61 which extends across all of the poles and which is securely clampedto the center-pole contact-arm 30 by means of split clamp 'I0 and ascrew I|. The three contact-arms are thus mechanically connected formovement together. Rectangular tubes 69 of insulating material betweenthe tiebar 61 and the contact-arms 30 for the several poles serve toinsulate the three movable contactarms and their associated contactsfrom the tiebar B1.

The movable contact structures and the stationary structures for theseveral poles are alike; hence only the contacts for the center pole areillustrated. The contact-arm 30 pivotally carries a main movablecontact-member 41 and a movable arcing contact-member 55 which cooperate,A

respectively with a main stationary contact 39 and a stationary arcingcontact 31. The stationary contacts 39 and 31 are secured to a conductor4I which extends through an opening in the base II Aand forms aterminal-connector 45. Contact pressure for the main co-ntacts isprovided by a spring 53 disposed between the contact-'arm 30 and `themain Amovable contact-member 41. Similarly, a spring [i3-providescontact pressure for the arcing contacts.

When the contact-arm 99 is moved to open the contacts, the arc drawnacross the arcing contacts 55--31 by rupture of the current is drawninto an arc-extinguisher indicated generally at 16 where it is cooledand extinguished. Any suitable arc-extinguisher may be employed, the oneshown comprising, generally; a stack of slotted plates (not shown) ofmagnetic material disposed adjacent the path of travel of the arcingcontact-member 55.

The movable arcing contact-member 55 is connected by a nexible shuntconductor 11 to the main movable contact-member 41, and another flexibleshunt conductor 19 connects the contactmember 41 to a conductor 8|. Theconductor 8| extends downwardly forming the energizing means for atripping electromagnet (to be later described) and is secured at itslower end by means of a bolt 82 to the inner end of a terminalconnector83 which, together with the terminalconnection 45, serves to connect thebreaker in an electrical circuit.

The electrical circuits for the several poles of the breaker areessentially the same. The circuit for the center pole extends from theterminal 45 through the conductor 4I, the main contactmembers 39--4'I,the flexible shunt conductor 19, the conductor 8| to the terminal 83.The circuit for the arcing contacts 31-55 extends from the terminal 45,through the conductor 4I, the arcing contact-members 31-55, the exibleshunt conductor 11, the main contact-member 41, and through thepreviously described circuit to the terminal 83.

The contact-arms 30 are biased in a clockwise or opening direction bymeans of a pair of springs (only one being shown). These springs aretensioned between the center-pole contact-arm 30 and a xed pivot 81supported in the main frame I1. In the closed position of the breaker,the center-pole contact-arm and consequently all of the contact-arms arereleasably restrained in the closed contact position by means of atoggle and linkage mechanism which is collapsible to cause opening oiAthe contacts. The toggle and linkage form a part of the common operatingmechanism.

This collapsible linkage includes a yoke-shaped lever 89 pivotallymounted on a xed pivot 9| supported on the main frame I1. The lever 89is operatively connected to the support arms 3| of the center-polecontact-arm 30 by a main operating toggle comprising toggle-links 93 and95. The toggle-link 93 has one end pivoted on a pin I0| supported on thelever 89, and the link 95 is pivoted on a pivot pin 99 in the arms 3 I.The links 93 and 95 are pivotally connected by a kneepivot pin 91. Thetoggle-link 95 comprises a pair of links rigidly connected by means ofan integral cross-bar H5.

The free end of the lever 89 is pivotally connected by means of a link|03 to one arm of a lever I 05 pivoted on the xed pivot 81. The otherend of the lever |05 is pivotally connected to a toggle-link |01 of atripping toggle comprising the link I 01 and a toggle-link |59. The link|09 is pivoted on a fixed pivot I|3 supported on the frame I1. Thetoggle-links |01 and |09 are pivotally connected by a knee-pivot pin I II. The lever |05 and the link |03 each comprises a pair of membersrigidly connected by yokes substantially as illustrated.

The above-described linkage serves to releasably hold the contactstructure including the movable contacts for all of the poles of thebreaker in closed Contact position. In the closed position, the mainoperating toggle 93-95 is over center above a line through the centersof the pins 99 and |0I, and a second toggle, one link of which comprisesthe overcenter links 93-95 and the other link of which comprises thelever 89, is over center above a line through the centers of the pins 99and 9|. The overcenter movement of the main operating toggle 93-95 islimited by the projecting end of the link 93 engaging the cross-bar I|5of the link 95.

Withthe main operating toggle 93--95 and the toggle comprising the links93-95 and the lever 89 in the overcenter position, the springs 85 biasthe lever 89 in a clockwise direction. Clockwise movement of the lever89, however, is normally prevented by the tripping toggle lill-|09 whichis restrained in a slightly underset position by a latch member |I'I(Figs. l, 2 and 5) cooperating with an extension I9 of the toggle-link|01. As will be described hereinafter, the latch-member I I'I may beoperated to release the extension ||9 and permit collapse of the toggle|01-I09 and opening of the contacts. In its restrained position, thetripping toggle I01|09, acting through the lever |05 and the rotation oithe handle Ml.

|203, prevents clockwisev movement of .the

lever 89, and consequently holds the movable llcontacts in closedposition against the biasing influence of the springs 85.

The latch-member ||1 is adapted to be actuated to cause collapse at thetripping toggle to efrect opening of the contacts by means of yanoverlcad-tripdevice indicated generally at |33,

.or by a shunt-trip device indicated generally at -of the trippingtoggle |51-|09. The shunt-trip device is adapted to be energized fromany suitable source separate from the circuit of the breaker to move thelatch ||1 axially and cause the` collapse of the tripping toggle HB1-|69 independently of the overload-trip device |33.

When rotated by the trip device |33, or moved axially upwardly by thetrip device |38, the latchmember ||1 releases the extension ||9 of thetoggle-link |51 and permits collapse of the tripping toggle |1|9 whichpermits clockwise rotation of the lever 89 thus permitting the springs85 to actuate the movable contact structure clockwise (Fig. 1) to openthe contacts.

vThe main operating toggle 93--95 does not immediately collapse, but theforce of the springs 85 applied through the vcontact-arms :fle- 3| .andthemain operating toggle causes collapse of the toggle comprising thelinks 93-95 and the lever 89 which results in a clockwise movement ofthe lever 39. This movement is transmitted through the link |03 and thelever |05 to complete the collapse of the tripping toggle |51-|59. Theclockwise or opening movement of the contact-arms Sii-3| is arrested byprojections (not shown) thereon striking the frame l1. At this time, therebound of the inertia of the mainoperating toggle 93-95 and the partsof the linkage B9, |03 and |35 starts the main-operating toggle 93-35over center in a direction to cause its collapse. By the time theknee-pin 91 of the toggle has passed over center below the line59-|3|,the weight of the parts acts to complete thecollapse'of thetoggle 93-95 and causes the linkage ae, sus, lus and the tripping toggleH11- |09 to be automatically reset to their normal holding positions andrelatched. The main toggle 93-95 remains in collapsed condition untilthe contacts are closed.

The contacts are closed manually by clockwise This movement of thehandle, through connections not shown, thrusts a link |5| downwardly,and, due to the engagement of the link with a projection |53 on ayoke-shaped closing lever |55, rotates the closl ing lever in aclockwise direction. The closing lever |35 comprises a pair of spacedlevers disposed on the outside of the frame l1 and are pivotallysupported on the fixed pivot 9|. Clockwise movement of the closing lever|45 engages a roller |55 pivotally carried on the inner end of trippingtoggle |51-ist has been restored to its holding position and relatched,rotation ofthe lever is prevented, and consequently the force applied bythe roller |55 to .straighten the operating toggle {i3-35 rotates thecontact arms3 vcounterclockwise to close the contacts and tension Ythesprings 35.

The handle lill' is restored to its normal posii tion by means of aspring |59 tensioned between rand slidable vertically on a pair of rodsthe closing lever |45 and the frame |11. Upon release of the handle:following a closing operation, vthe spring |59 moves the closing lever|45 counterclockwise and, through the projection |53 and link i5|,restores the handle |4| to its normal position.

The closing lever |45 may also be operated to automatically close. thecontacts through the agency of amotor 535| mounted on al plate (notshown) but which is attached to the side of the frame I1. The motor |39may be energized romany suitable source, and when energized isadapted,through a` suitable driving connection, to rotate a crank disc |38. Thedisc |30 carries an anti-friction roller |31 which, upon rotation of thedisc, engages a cam face |32 on an arm |34, secured to the closing lever|45, and rotates the arm and the closing lever clockwise to reieetclosing of the contacts. As soon as the roller |35 passes out ofengagement with the arm |36, the spring lg acts to restore the lever |45to its normal position. The motor |39 is deenergized by a suitable limitswitch (not shown).

The circuit breaker may be tripped manually by rotation of the handleilll through a small angle in a counter-clockwise direction from itsneutral position. Rotation of the handle |4| in tripping directionengages a projection |51 on the link |51 with an ear |5| formed on aplate |53 (Fig. 2) secured to a slide |65 disposed in an opening in thecross-member 25 of the frame I1 |61 mounted in the cross-member 25 ofthe frame. Thelower portion of the slide |65 is formed over to provide alaterally extending part |59 which is adapted to engage a head on theend or" a projection |13 integral with or otherwise suitably attached tothe latch-member H1. Upon rotation o f thehandle |l|| (Fig. l) intripping direction, the lii k |5| is moved upwardly. During thismovement, the projection |51 (Fig. 2) engages the ear 56| and raises theslide |55. This movement engages the extension |55 with the head |1| andraises the latcli-inember i i1 to efect release of the tripping toggle|51-|65 and openingof the contacts.

As previously set forth, the latch member ||1 is rotated to release theunderset tripping toggle lili-|39 by means of the current-responsivetrip-device |33. rlhere is a trip-device |33 provided foleach pole ofthe breaker, but since the trip-devices for the several poles are alikeonly the one for the center pole shown in Figs. 2 and 3 -will bedescribed. Y

The trip-device |33 (Figs. 2 and 3) includes a. Viixed magneticcore-member |15 provided with `pole-pieces |11 secured thereto by meansof bolts |19 which also serve to clamp the parts to an insulating frame|8|. rIhe core-member |15 is vsurrounded by an insulating tube |83 toinsulate it from the energizing conductor 8| which is looped around thecore member between the polepieces |11. The frame |8| is provided with across-member |85 integral therewith which is secured to the base il ofthe breaker by means ci the bolt S2 by which the conductor 8| and theflexible conductor 1Q are secured together and to the base i Mounted forrotation in the frame |8| is a shaft |31 having the legs |89 oi a yokeor trip-bar mounted thereon for movement relative thereto, the trip-bar|9| being operable by the trip-devices for all the poles. A headed andshouldered stud |33, secured to the yoke |9| by a nut |95, projectsthrough an opening in a 229 and spacers 24| elink' |91 which connectsthe trip device to a time delay device indicated generally at 2 I 3. Theinner end of the link I 91 is formed over at right angles as at I 99 tocooperate with an armature 20| mounted on the shaft |31 for movementrelatively thereto. The armature 20| is biased to unattracted positionas shown in Figure 2 by means of a spring 203 having one end attached toa spring-clip 205 secured to the free end of the armature and the otherend attached to an adjustable member 201. The member 201 has a reducedportion disposed in a vertical slot 209 in the outer wall of the frameIl and is provided with a thumb-screw 2| I for clamping the member 291in its adjusted position in the slot 209. By loosening the thumb screw2| I and sliding the member 201 in the slot 209, the tension of the.spring 293 may be varied thereby varying the minimum current value atwhich the trip-device l'will function to trip the breaker.

The trip-devices for the two outer poles of the breaker are the same asthe trip-device for the center pole with the exception that the yoke ortrip-bar i9! is omitted and the armatures 20| for the outer poles aresecured to the corresponding shafts |81 for movement therewith. On theend of the shaft |91 adjacent the center-pole tripdevice is secured acollar 2I5 (Fig. 3) having a projection 2i1 thereon which is adapted toengage a shoulder on a connector 2|9 of insulating material. Theconnector 2|9 is secured to a hub 22| which is rotatably mounted in abearing in the side-wall of the frame IBI and is secured to the leg |39of the yoke |9I for movement therewith. Two connections 2|9 areprovided, one disposed on each end of the yoke |9| for operativelyconnecting the two outer pole-armatures 20| to the yoke so that any oneof the armatures -will operate the yoke, upon energization of itscorresponding trip-magnet, without displacing the other armatures.

The link |91 (Fig. 2) comprises two members welded or otherwise suitablysecured together at their left-hand ends and having their right-handends formed to straddle a ratchet-wheel 223 (Figs. 2 and 3). Theratchet-wheel 223 is rotatably supported in a housing comprisingspacedcircular plates 225 and a cylindrical side-wall 221. The upperplate 225 is secured to the lower leg oi a U-shaped bracket 229, whichsupports the shunt 'trip-device |38, by means of a pair of bolts 23| andis spaced from the bracket by spacers 233 surrounding the bolts 23| (seealso Fig. 4).

The upper leg of the bracket 229 is secured to the spaced mainframe-members of the circuitbreaker by means of a pair of screws 235(only one being shown) and a pair of bolts 231 which extend through bothplates 225, both legs of the U-shaped bracket 229 and threadedly engagethe frame-members |1. Spacers 239 (Figs. 2 and 4) surrounding the bolts231 serve to space the timedelay housing from the lower leg of thebracket (Figs. 2 and 3) also surrounding the bolts 231 space the upperand lower plates of the time-delay device-housing apart..

The plates 225 are also rigidly joined by a headed screw 243 (Fig. 2)which passes through an opening in the lower plate and threadedlyengages the upper plate 225. Surrounding the screw 243 is a sleeve 245upon which is mounted a shouldered sleeve 241 supporting the ratchetWheel 223.

As previously stated, the bifurcated end of the link |91 straddles theratchet-wheel 223. The link |91 is connected to the ratchet-wheel bymeans of a pin and slot-connection comprising a pin 249 (Figs, 2, 3 and4) which extends through both' portions of the link |91, through anelongated slot 25| (Fig. 3) in the ratchet-wheel 223 and through aclearance-opening 253 (Fig. 4) in the upper plate 225 of the housing ofthe timedelay device. The lower end of the pin 249 is headed and acollar' 255 threadedly engages the pin above the upper portion of thelink |91 to retain the pin 249 ini place in the assembly. The

pin 249 projects through the clearance-opening 253 in the upper plate225 for the purpose of `rotatably actuating the trip-member |I1 (Fig.

2) to trip the breaker in a manner more fully described hereinafter.

A spring 251 (Figs. 2 and 3) coiled about the -sleeve 241 has one endhooked around the pin 249 and the other end hooked over the ratchet-Wheel 223 in the manner shown in Fig. 3. Normally the spring 251 is notunder tension, but when the link |91 is-moved toward the left (Fig. 3)by the operation of the electromagnetic trip device of any one of thepoles of the breaker, the pin 249 places the spring under tension in adirection to cause counter-clockwise rotation of the ratchet-wheel 223.The speed of rotation of the ratchet-wheel is governed by an oscillator259, the two arms of which alternately engage the teeth of the ratchetin the usual manner.

The oscillator 259 is U-shaped and is mounted for oscillation on a pin26| which is mounted in the legs of a U-shaped movable member 263pivoted on the ends of the sleeve 245 surrounding the screw 243. Thespaced ends of the upper leg of the oscillator 259 are formed downwardlyas at 265 (Figs 2 and 3) to engage the ratchetwheel. The lower leg ofthe oscillator extends to the left to form a governing weight for theoscillator, a clearance opening being provided therein for clearing thesleeve 241.

The amount of time-delay provided by the time-delay device is adjustablydetermined by adjusting the oscillator circumferentially relative to theratchet-wheel. This adjustment is eiected by rotating the member 263 inwhich the oscillator is mounted about its pivot on the sleeve 245. Thisadjustment is accomplished by means of a thumb-screw 261 having athreaded portion extending through an elongated annular slot in theside-wall 221 of the housing and threadedly engaging the yoke of themember 263. By loosening the thumb-screw 291 and rotating the U-shapedmember 263 counter-clockwise o1` clockwise the oscillator iscorrespondingly moved in the same direction from the position in whichit is shown in Figure 3, respectively, lengthening or shortening thetime-delay.

As previously stated, the pin 249 projects through the clearance-opening253 (Fig. 4) in the upper plate 225 of the time-delay device housing tooperate the latch-member I|1 and effect tripping of the breaker. Thelatch-member II1 is rigidly secured on the upper end of a trip rod 269which extends vertically through the center of the shunt trip-device|38. A disc 21| secured on the lower end of the rod 269 is provided withtwo recesses 213 and 215 (Fig. 4). The pin 249 (Figs. 2, 3 and 4)extends upwardly through the recess 213 and a substantial distance abovethe disc 21|. The side-walls of the recess 215 are adapted to engage astop-stud 211 which projects upwardly from the upper plate 225 to limitthe rotary movement of the disc and of the latch-member I1.

Referring particularly to Figs. 5, 6 and 7 of the drawings, thelatch-member I|1 is provided with a, vertically disposed zslot 219intowhich the projection |I9 ofthe tripping toggle-link |01 extends. Theprojection H9 has Ya latching. shoulder 28| which normally rests'against the periphery `of the latch-member to restrain the trippingtoggle `in its slightly under-set holding position. At the point ofYlatc'hing engagement of the shoulder 28| with the latch-member, theslot -219 has straight parallel sides and is-\disposed at a slight anglerelative to the projection H9 as shown in Fig. 6. At the point where'the Yprojection I9 extendsinto the slot `219,the 'sides Aof the lslotare ared as shown in Fig. I to permit unlatchin'g rotation of thelatch-member;

The operation of the trip device and time-delay device is described as`follows: Upon the "occurrence `of an yoverloali-current in `any pole ofthe breaker below -a predetermined value, /for instance, below' i000 ofnormal rated current, the armature 20| of the affected `pole isattracted lby the xed magnetic co're member and pole-pieces. If theoverload occurs in one of the outer poles oi the breaker, the armatureoperates through the projection 2| 1 (Fig. v3) to yactuate the yoke ortrip-bar |"9I and movet'h'e link `|91 toward 'the left. If the overloadoccurs in the center pole, the armature engages 'the formed `over-endE99 of the link E91 to move the link toward the left. Leftwardkrrrovement of kthe link '|91 through 'the pin 2'49 Yandsbring 251rotatestheratchet-wheel 223 counter-clockwise (Fi'g; 3) under thecontrol of the 'oscillator 259 witl'ioutk :substantially increasing thektension of tl'ie'spring 251. After the mechanism has operated apredetermined distance the pin `2li9=engages the 'wall 4or the recess2-13 (Fig. 4) in the disc'21| 'and rotates thedisc 21|, the ro'd 269rand the latch H1 counter-clockwise until arrested by the wall of therecess 215 striking the stop-stud 211. The movement `of the disc 21|`and the latch-member ||`1 'after the engagement of the pin 2119 w-iththe `disc is 4suiiicient `to align the straight portion fof the slot219` (Fig in the latch-member with the latching shoulder 281 on `theprojection -l'|9 thereby permitting collapseof the tripping toggle191;!! 09 (Figs. 1 and 2) 'and opening `of the contacts in the mannerpreviously described;

The 'ratchet wheel 223 is provided with a hat surface 28S the one `end`of which, during a tripping operation, passes the `lowerarm of theVoscilz lator, whereupon the pull v:oi the magnet is unrestrained andinstantaneously moves the pin 249 the 'remaining distance'to tripthebreaker. By moving `the oscillator relative to the ratchet-- wheel sothat "a greater or-lesser number of teeth f f is lrequired to pass theoscillator before 'the wheel escapes from the oscilator, a longer orshorter time-delay may beeffected.

As soon vas the current is interrupted. and the trip magnet isfdeenergized, the spring 2% to restore the armature 29| of the aii'ectedpole to its unattractedposition. The yoke lill, linl; i 91 'and thetime-delay'fdevice are .restored to their unoperated posi-tions by meansof 28,? 2 and 35 having one end attache to the lower ends of the legs|89V oi the yoke lill auf?, having their oth'erends attached tospring-st proj ecting'irom the sides `oi vthe housing The provision 'ofthe mechanical escape timeedelay device #connected to the tripping "-f-cmakes the trip-device shockproof since the i9! (liig. 2) is firmlyrestrained against y`one tion in response to shocks and jarring forcesto .ertia of `the .ratchet-wheel. oscillator-'259.Undesrabletrippingoperation l(il) 'i two core-members 285 and ESE.

the latch IIT in response to shocks transmitted to the trip-device in ahorizontal direction through the supporting structure ii and |81 andalso through the supporting structure I'1-229 to the time-delay device,is thereby prevented.

As was previously set forth, the latch-member H1 is moved axiallyupwardly by means of the shunt trip-device 538 to release the trippingtoggle Nfl-|89 to thereby cause collapse of the operating linkage andopening of the contacts. The shunt trip-device comprises a movablecore-'nember 285 of magnetic material and an energizing winding 281. Themovable core-member 285 is secured to a reduced portion of the rod 269by means of a pin 2535 and is adapted to iii-t the rod upon energizationof the winding 281. The movable core member is disposed for verticalmovement in a tube 289 of non-magnetic material, the ends of which areseated in counterbores in the upper and lower legs -of the U-sha-pedframe i229.. The winding 281 is wound on a tube 291i of insulatingmaterial surrounding the tube 239 and is insulated from the legs 'of thebracket 229 by means 'of insulating plates 293.. Disposed in the tube285! above the movable core-member 225 is a secondary-movablecore-member 295 also oi magnetic material. The secondary core-member 295is spaced apart from the movable core 285 by means of Aa spring 2.91coiled about the rod 269, and is movable axially relative to kthecoremember 285 and the rod 259. The spring 2M is seated on top of themovable core 285 and in a counterbore in the secondary core 295.

The Winding 281 is energized from any suitable source (not shown) eitherautomatically or by the closure of a manually operable switch (also notshown) in the energizing circuit. When the coil is energized, themovable core 285 is v attracted upwardly and thrusts the rod 259 and thelatch-member H1 upwardly to free the tripping toggle ISI- |09 in themanner previously described in connection with the description of themanual tripping of the breaker. The upward movement of the rod 25S latchi l1 limited by the dise 21! on the lower end of the rod striking amer-cher 299 secured to the bottom leg of the racket 229. Upondeenergization oi the winding 281, the movable core 285, the secondarycore 295, the trip-rod 25.59 and the latch li'l are all restored totheir normal unattracted positions by the force of gravity.

The purpose of the separate secondary coremerrber 235 and the spring 291is to absorb the kinetic energy of tbe movable core 2525, the rod 2559and the latch H1 imparted thereto as a result voi shocks or iarriugforces, and thus prevent undesirable tripping of the breaker in respouseto shocks. The only force due to shock that would cause false tripping'movement of the movable core v235 and the trip-rod "e in a verticaldirection and comes from the s ing struc-ture i l, l1 and 239. shock intical direction imparted to the "ing ystructure will he transmitted tothe mov which results in accelerating the movable and the trip-rod 293.3upwardly in trippincA direction. The spring 29.1! is relatively we andserves only to providea desirable air-gap h W the rievab'le core Zandtrip-rod 25% are moved upwardly in response to shock, the secondary core295 will remain. substantially stationary until movable core strikes it.When this occurs, the sec- '-2'A cndarycore .295 is accelerated upsfsrdythereby absorbing substantially all of the kinetic energy of the movablecore 285. At the same time, the spring 2t? was compressed as the movablecore 285 approached the secondary core 2&5, and the energy storedtherein reacts to move the secondary core 295 upwardly. The result isthat. after the collision of the core-members, the secondary core 295,having a higher rate of acceleration than the movable core 285, willrebound from the upper leg of the bracket 229 and strike the movablecore 285, thus providing an additional retarding force which is eiectiveto prevent upward movment of the latch ii'i and tripping of the breakerin response to sudden shocks or jarring forces.

From the foregoing description it will be apparent that there isprovided a circuit-breaker having a main latch which is movablerotatably by any one of a plurality of overload t 'ip-devices to tripthe breaker and movable axially by a separate trip-device to trip thebreaker. There is also provided a mechanical time-delay device 'fordelaying tripping of the breaker by any one of the plurality oftrip-devices, the time-delay .flevice also serving to prevent rotarytripping operation of the latch in response to shocks. There is alsoprovided means for preventing axial tripping movement of the latch inresponse to shocksy A further advantage of the invention lies theadiustment of the oscillator of the time-delai-7 device relative to theratchet-wheel to vary the arpount of time-delay.

While the invention has been disclosed in accordance with the provisionsof the patent statutes` it is to be understood that various changes inthe structural details thereof may be without departing from the spiritof the invention.

We claim as our invention:

l. T.n a multi-pole circuit breaker, relatively movable contacts,operating mechanism for said contacts. latch means for releasablyrestraining said operating mechanism in closed position, said latchmeans being rotatable and movable axially to release said operatingmechanism to thereby cause opening of said contacts, electroresponsivemeans for each pole operable in response to predetermined circuitconditions in. the associated pole.. a trip member operable by least twooi said electroresponsive means to rotate lai-ch and release saidoperating mechanism, timedelay device operatively related to said tripmem-- ber for delaying operation of said latch, eleetroresponsive meansfor moving said latch axially independently of said time-delay device torelease said operating mechanism.

2. in a multi-pole circuit breaker, relatively movable conte cts foreach pole, operating comprising a linkage normally holding said contantsclosed and collapsible to effect opening of said contacts, latch meansfor restraining said linkage in holding condition, said restrainingmeans being operable in two directions to release said linkage,electroresponsive means for eachI pole operable in response topredetermined circuit conditions in the corresponding pole to operatesaid latch in one direction, a time-delay device operatively related tosaid electroresponsive means to delay operation of said latch in saidone direction, and separate electroresponsive means for operating saidlatch in another direction independently of said time-delay device torelease said linkage.

3. In a multi-pole circuit breaker, relatively movable contacts for eachpole, operating means comprising a linkage normally holding saidcontacts closed and collapsible to eiect opening oi said contacts, meansfor restraining said linkage in holding condition, said restrainingmeans being operable in two directions to release said linkage,electroresponsive means for each pole operable in response topredetermined circuit conditions in the corresponding pole to operatesaid restraining means in one direction., a timedelay device comprisinga mechanical escapement device operatively related to saidelectroresponsive means to delay operation of said restraining means insaid one direction, and separate electroresponsive means for operatingsaid restraining means in another direction independently oi' saidtime-delay device to release said linkage, said time-delay device actingto prevent operation of said electroresponsive means in response to butonly during the existence oi sudden shocks or .iarring forces.

4. In a multi-pole circuit breaker, relatively movable contacts for eachpole, an operating mechanism for said contacts, a rotatable latchoperable to cause circuit-opening operation of said operating mechanism,said latch being also movable axially to cause, circuit-openingoperation of said operating mechanism, a trip member common to at leasttwo of the poles and operable to rotate said latch, electroresponsivemeans for each pole operable in response to abnormal circuit conditionsin the related pole for operating said trip member, a time-delay devicefor retarding operation of said trip member androtation of said latch inresponse to abnormal cirf cuit conditions below a predetermined valueoccurring in any pole of the breaker, means relating said time-delaydevice to said trio member to permit said trio member to instantaneouslyrotate said latch in response to abnormal circuit conditions above saidpredetermined value, and. a trip device operable to move said latchaxially in dependently of Said trip member and said timedelay device totrip the breaker.

5. In a circuit breaker comprising an operating mechanism, a trip deviceincluding a tripping toggle operable to effect circuit opening operationof said operating mechanism, latch means restraining said toggle andmovable rotatably and axially to release said toggle, an electromagnetincluding an armature operable upon en ergization of said magnet torotate said latch means to release said toggle, a time-delay device fordelaying rotation of said latch means by said armature. and a secondelectrnmagnet operable when energized to operate said latch meansaxially independently of said time-delay device to release said toggle,said time-delay device opposing rotary operation of said latch mea ns bysaid armature in response to sudden shocks or jarring forces, and meansfor preventing axial operation of said latch means in response to suddenphysical shocks or .iarring forces.

' 6. In a multi-pole circuit breaker, an operating mechanism including atoggle operable to permit circuit opening operation of said mechanism,means restraining said toggle in operative position. said restrainingmeans being movable rotatably and axially to release said toggle, a tripbar common to at least two of the poles for rotating said restrainingmeans to release the toggle, electromagnetic means operable in responseto abnormal circuit conditions occurring in any pole of the breaker tooperate said trip bar, separate electromagnetic means operable whenenergized to directly 'operate Vsaid restraining means. ax-

ially to release said toggle, time-delay means comprising a mechanicalescapement device for at times delaying rotation of said restrainingmeans, said time-delay means acting to prevent rotation of saidrestraining means by the rst named electromagnetic means in response toshocks or jarring forces, and a member engageable by said separateelectromagnetic means when said separate electromagnetic means is movedin response to physical shocks or jarring forces to oppose axialtripping movement of said restraining means.

7. In a circuit breaker comprising relatively movable contacts andoperating mechanism for said contacts including a toggle operable toeffect circuit-opening operation of said operating mechanism, a latchfor restraining said toggle in operative position, said latch having anelongated slot therein through which a portion of said toggle extends, arst electromaget operable when energized to rotate said latch to releasesaid toggle, a second electromagnet operable when energized to move saidlatch longitudinally to release said toggle, a time-delay device forretarding tripping rotation of said latch by said rst electromagnet, andmeans cooperating with said second electromagnet to prevent longitudinaltripping movement of said latch in response to sudden shocks or jarringforces.

8. In a circuit breaker comprising an operating mechanism, meansreleasable to effect circuit opening operation of said operatingmechanism, latch means releasably restraining said releasable means,said latch means being rotatable and also movable axially to releasesaid releasable means, electroresponsive means operable when energizedto rotate said latch means to release said releasable means, means forpreventing rotation of said latch means in response to sudden shocks,electroresponsive means operable when energized to move said latch meansaxially to release said releasable means, and means comprising a massdisposed to prevent axial move- 14 ment of said latch means in responseto sudden shocks or jarring forces.

9. In a circuit breaker comprising an operating mechanism therefor',means releasable to effect circuit opening operation of said operatingmechanism, latch means releasably restraining said releasable means,said latch means being rotatable and also movable axially to releasesaid releasable means, a rst electroresponsive means operable whenenergized to rotate said latch means to release said releasable means,means for preventing rotation of said latch means in response to butonly during the existence of sudden shocks, a second electroresponsivemeans operable when energized to move said latch means axially torelease said releasable means, and an inertia member cooperating withsaid second electroresponsive members for preventing axial movement ofsaid latch means in response to but only during the existence of suddenshocks or jarring forces.

LEON R. LUDWIG.

WILLIAM H. STUELLEIN.

GAYNE D. GAMEL.

REFERENCES CITED The following references are of record in the le cithis patent:

UNITED STATES PATENTS Number Name Date 522,527 Larson July 3, 1894832,705 Stewart Oct. 9, 1906 1,120,222 Murray et al Dec. 8, 19141,123,288 Hellmund Jan. 5, 1915 1,280,595 Van Wijk Oct. 1, 19181,866,808 Ireland July 12, 1932 2,081,727 Barenyi May 26, 1937 2,340,973May et al Feb. 8, 1944 FOREIGN PATENTS Number Country Date 196,305 GreatBritain Apr. 11, 1923

